Which of the following contains the highest number of helium atoms?

1. 4 u of helium
2. 4 g of helium
3. 2.27 L of helium at STP
4. 4 mol of helium
Subtopic:  Moles, Atoms & Electrons |
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NEET - 2024
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1 gram of sodium hydroxide was treated with 25 mL of 0.75 M HCl solution, the mass of sodium hydroxide left unreacted is equal to :

1. 250 mg
2. Zero mg
3. 200 mg
4. 750 mg 
 
Subtopic:  Millimole/Equivalent Concept |
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NEET - 2024
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A compound X contains 32% of A, 20% of B and remaining percentage of C. Then, the empirical formula of X is :
( Given atomic mass of A=64; B=40; C=32u)
1. ABC3
2. AB2C2
3. ABC4
4. A2BC2
 
Subtopic:  Empirical & Molecular Formula |
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NEET - 2024
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4.74 g of an inorganic compound contains 0.39g of K, 0.27 g Al, 1.92 g of \(\mathrm{SO_4}\) radicals and 2.16 g of water. If molar mass of the compound is \(948 \mathrm{~g} \mathrm{~mol}^{-1},\) the molecular formula of the inorganic compound is:
1. \(\mathrm{KAl}\left(\mathrm{SO}_4\right)_2 \cdot 12 \mathrm{H}_2 \mathrm{O}\)
2. \(\mathrm{K}_2 \mathrm{Al}_2\left(\mathrm{SO}_4\right)_6 \cdot 12 \mathrm{H}_2 \mathrm{O}\)
3. \(\mathrm{K}_2 \mathrm{SO}_4 \cdot \mathrm{Al}_2\left(\mathrm{SO}_4\right)_3 \cdot24 \mathrm{H}_2 \mathrm{O}\)
4. \(\mathrm{K}_2 \mathrm{SO}_6 \cdot \mathrm{Al}_2\left(\mathrm{SO}_4\right)_3 \cdot12 \mathrm{H}_2 \mathrm{O}\)
Subtopic:  Empirical & Molecular Formula |
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NEET - 2024
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Molar mass of a compound \(\text{(X)}\) whose \(2.6 \mathrm{~mol}\) weighs \(312 \mathrm{~g}\) is:

1. \(312 \mathrm{~g} \mathrm{~mol}^{-1}\)
2. \(120 \mathrm{~g} \mathrm{~mol}^{-1}\)
3. \(60 \mathrm{~g} \mathrm{~mol}^{-1}\)
4. \(811.2 \mathrm{~g} \mathrm{~mol}^{-1}\)
Subtopic:  Empirical & Molecular Formula |
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NEET - 2024
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The mass of  CO2 produced by heating 20 g of 20% pure limestone as per the given below equation is:
  \(\left[\mathrm{CaCO}_3 \stackrel{1200 \mathrm{~K}}{\longrightarrow} \mathrm{CaO}+\mathrm{CO}_2\right] \)
1. 1.32 g  2. 1.12 g 
3. 1.76 g  4. 2.64 g
Subtopic:  Equation Based Problem |
 72%
From NCERT
NEET - 2023
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Select the correct statements from the following: 
A: Atoms of all elements are composed of two fundamental particles.
B: The mass of the electron is \(9.10939 \times 10^{-31} \mathrm{~kg} \text {. }\).
C: All the isotopes of a given element show same chemical properties.
D: Protons and electrons are collectively known as nucleons. 
E: Dalton's atomic theory regarded the atom as an ultimate particle of matter. 
Choose the correct answer from the option given below: 
1. B, C and E only  2. A, B and C only 
3. C, D and E only  4. A and E only 
Subtopic:  Introduction |
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NEET - 2023
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The density of 1 M solution of a compound 'X' is 1.25 g mL–1. The correct option for the molality of  solution is:
(Molar mass of compound X = 85 g): 
1. 0.705 m  2. 1.208 m 
3. 1.165 m  4. 0.858 m 
Subtopic:  Concentration Based Problem |
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NEET - 2023
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Calculate the mass of 95% pure CaCO3 that will be required to neutralize 50 mL of 0.5 M HCl solution according to the following reaction.
CaCO3(s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + 2H2O(l)
[Calculate up to the second place of decimal point]
1. 9.50 g 2. 1.25 g
3. 1.32 g 4. 3.65 g
Subtopic:  Equation Based Problem |
 52%
From NCERT
NEET - 2022
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Match List-I with List-II:

List-I List-II
(a) 4.48 litres of O2 at STP (i) 0.2 moles
(b) 12.022 × 1022 molecules of H2O (ii) 12.044 × 1023 molecules
(c) 96 g of O2 (iii) 6.4 g
(d) 88 g of CO2 (iv) 67.2 litres at STP
(Given - Molar volume of a gas at STP - 22.4 L)
Choose the correct answer from the options given below:
(a) (b) (c) (d)
1. (i) (iii) (iv) (ii)
2. (iii) (i) (iv) (ii)
3. (iv) (i) (ii) (iii)
4. (iii) (i) (ii) (iv)
Subtopic:  Moles, Atoms & Electrons |
From NCERT
NEET - 2022
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